BioReliance acquired again

Rockville-based BioReliance Corp. is being sold for the third time since 2005.

BioReliance, which provides clinical testing services, is being sold by its current majority owner, Avista Capital Partners, to Sigma-Aldrich Corp. for $350 million. Avista acquired BioReliance from Invitrogen, now Life Technologies Corp., in 2007 for $210 million.

BioReliance was taken private by Invitrogen in 2005.

Diagnostic test kit maker Sigma-Aldrich’s (NASDAQ: SIAL) acquisition of BioReliance is still subject to regulatory approval, but is expected to close sometime this quarter, the companies said.

BioReliance is one of Maryland’s oldest biotechnology companies, founded in 1947. The company has 650 employees at operations in Rockville, Scotland, Japan and India.